谈三步投掷技术的优越性

三步投掷标枪技术，能够发挥水平速度、预先速度、助跑后左腿支撑制动时获得的人体转动速度、最后用力过程中器械的加速度，因此在我国中小学体育教学，课外训练中，学习三步掷标枪技术，可为我国家培养标枪的后备力量创造良好的基础。     

投掷运动员爆发力训练探讨

中学生投掷运动员由于平时训练缺乏系统性和科学性,只是在比赛前进行短时间的突击训练,且急于求成,不但容易损伤身体,成绩也不理想。因此,要正确处理文化课学习与体育训练的关系,制订科学持久的训练计划,提高身体素质,熟练掌握运动技能,特别要加强爆发力训练。一、爆发力与运动成绩我们知道,决定投掷成绩有三个因素:初速度、出手角度和空气阻力。在出手角度和空气阻力不变的情况下,器械的初速度越大,成绩越好。要想提高初速度就必须提高肌肉的收缩力量,加大用力距离和缩短用力时间,即提高爆发力。如果用公式来表示,即:爆发力=力量×速度。为了提高初速度,采用滑步、旋转与助跑的方法,来获得一定的速度,再与投掷速度迭加,最后增加了器械的初速度。在具体的训练中,就是通过滑步、旋转和助跑等过程使肌肉在快速较大幅度拉长的情况下,快速收缩产生更大的力量。二、产生爆发力的原理在投掷运动中,运动员通过滑步、旋转和助跑等过程获得一定的速度。同时,又在这些运动过程中,通过不同的形体动作而产生最大的爆发力。1、滑步过程中推铅球最后用力是从脚落地到身体形成侧弓,由于上体不主动抬起,头颈不扭转,而使身体一侧的有关肌群形成最大的拉紧形态,为最大的加速而创造了有利条...     

论人体髋部正确运动形态对投掷最后用力的影响

投掷铅球、标枪的最后用力动作 ,是各项投掷运动取得优异运动成绩的关键技术。本文论述了人体髋部正确运动形态对投掷最后用力的影响。     

掷铁饼与技术动作分析

掷铁饼是一项技术性很强的运动,投掷臂动作,左肩动作,左腿动作以及躯干动作对掷铁饼的最后用力有着重要的影响,应充分利用这些技术动作提高投掷成绩。     

对当代掷铅球、铁饼、标枪五个重要技术理论的运动生物力学分析

一,前言通过观摩和查阅中外体育科技资料了解到,在掷铅球、铁饼、标枪技术理论中有五个重要问题应进一步研究:(一)当前对三项投掷运动助跑的作用,有两种观点:一是使器械在投掷之前获得速度;二是在投出器械之前取得良好的超越器械姿势。(二)关于三项投掷最后用力阶段的划分,在阅读过的所有资料共同的论述是,掷铅球滑步、掷铁饼旋转、掷标枪交叉步后,右脚落地到左脚落地投出器械,称为最后用力阶段。(三)最后用力时人体发力的时间,有两种不同的观点,其主要区别在于三项投掷运动     

新型男子标枪最后用力技术研究

运用运动解剖学、生物力学理论及数理统计方法，对新型标枪最后用力、出手角度、出手初速度等因素进行分析．结果表明，最后用力技术动作的关键，是把握好髋部运动的用力时机，在快速助跑中应不停顿地完成最后用力技术，掌握好合理的出手角度，加快出手时的快速鞭打投枪动作     

标枪出手后的飞行轨迹与最后用力的关系

通过多年的标枪教学实践中的归纳总结、观看录像、查找资料法等方法对标枪飞行弧线与最后用力技术群关系的分析研究,根据标枪出手后在空中出现不同的飞行和滑翔形式,把标枪的整个飞行轨迹分成了四种不同的类型,结果是不同的飞行轨迹同最后用力瞬间姿势动作密切相关.现代标枪的特性决定了只有选择适合现代标枪飞行轨迹类型的投掷技术,才能使标枪投掷的更远,为标枪的教学与训练提供更有价值的参考.     

对标枪最后用力左侧支撑技术的分析

掷标枪是一项复杂的技术,在标枪的“持枪与握枪、助跑、最后用力和出手后的平衡”四个技术部分中,最后用力起着至关重要的作用。而在最后用力技术环节中,左侧支撑技术的好坏,直接影响力的传递和用力的效果,进而影响投掷成绩。     

掷标枪最后用力技术教学方法研究

本文采用文献资料、实际调查和教学实验对掷标枪最后用力技术的训练方法和最后用力技术中投掷臂的动作以及顺标枪纵轴用力技术教学方法进行研究。指出：在最后用力时,合理的用力顺序是取得最大出手速度的关键,身体左侧的支撑用力动作对于投掷成绩起着至关重要的作用。     

试析推铅球的最后用力技术

运用生物学等原理，对铅球飞行轨迹进行计算分析，提出影响铅球运行远度的因素和最后用力对运动成绩起的决定性作用，并运用人体解剖学和生物力学的方法对最后用力各个环节的技术进行全面分析，提出激发肌肉潜能，加速运作节奏，以适宜的角度，合理的高度和最快的出手速度投掷铅球的规范动作标准。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

橡胶颗粒沥青混合料低温抗裂性试验研究

以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

Quantitative trait loci （QTLs） for quality traits related to protein and starch in wheat

Quality traits in wheat （Triticum aestirum L.） were studied by quantitative trait locus （QTL） analysis in a recombinant inbred line （RIL） population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross （ChSh）. Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.